My car is still backfiring. I took it in for emissions a couple weeks ago and it passed. When I was driving home from the inspection station in Manassas and a cop pulls me over because of my expired inspection sticker. I showed him the sheet from the emissions place and he let me go. Here's where I start to have a problem. About a mile after where I got pulled over I thought my header was coming loose again because there was a loud noise. Once I got home though I realized it was backfiring and not the header.

Aside from the service station putting a new battery in I haven't changed anything on the car in a while. In fact I haven't been driving it much. The car has 125k (15k on engine), the original ig. coil, distributor, and fuel pump. The plugs, wires, rotor/cap, are all new.

One thing I noticed when I got home was the distributor was really loose. I guess I left it loose a while ago so I could change the timing without having to take apart that whole mess behind the plenum.

Here's some of the things I've checked:

unplugged computer for 1 hour to erase memory, double checked the timing, checked for spark, scanned the codes. I got a code 43 but I think that was because I unplugged the ground wire when checking the timing. Oh yea, when I unplugged the ground wire, the car stopped backfiring.

Thanks in advance,
Mike89GTA

 

You need to re-adjust the timing and tighten the distributor hold down screw. With the set timing plug unplugged the ECM has no control on the timing.

 

Yea I did that but it still backfires.

 

Retard your timing to 0 degree's


See if your back firing stops, if it gets better retard it more.

Its obviously timing related if when you unplug your EST it stops back firing.

 

Oh yea...


If your distrib was TO loose it could have jumped a tooth

something else to look at.

 

Is the back firing as you call it coming from the tail pipes or out the throttle body? Check your fuel pressure also. If low or high, it can give same effect

 

Did you unplug the Elect Spark Advance wire when you set the base timing. If your distr was loose that has to be it. Good Luck!!